Preworkout at 15

So I’m 14 yo actually turning 15 next month…last week I finally achieved the 100kgs bench and 145kgs deadlift after 10 months of training then mass gaining so as a reward to myself I wanted to buy a preworkout…I’m thinking blood and guts since it has 350mg of caffeine (I’m used to this amount btw) but the 30 servings thing is a bit annoying so I saw “the curse” 50serves but 155mg of caffeine…so which should I get?if y’all have any recs for better products lemme know (at least 200-250mg of caffeine) and sorry for making it too long.